Had a fly away that landed in the lake

[Meta4]

Thank you Meta! I am new to this, so I just figured out how to view my flight log with Air Data. I attached it. I was also able to view my flight and controls through the DJI app. I don't see me pressing down on the left joystick for it to descend.

There some disturbing altitude instability showing up in your flight data from 3:21.5 when you briefly pulled the left stick full down and the drone started slowly climbing from 31 ft to 48 ft at 3:33 even with the left stick down a couple of times and never being pushed upwards.
From 3:33 the drone started coming down very slowly though the left stick was full down (in tripod mode).
You left the left stick in the centre position from 3:37.2 but the drone continued to descend, but climbed from 3:40.6.
At 3:42.2 (40 ft) you pulled the left stick down and the drone descended as it should have and stopped descending when you centred the stick soon after.

But at 3:46 the real trouble showed.
With the left stick centred and the drone hovering, it started losing height.
Within 2.8 secs it hd lost 30 ft.
You went to sport mode and full left stick up to fight the drop.
But it continued to fall.

I see you were using Firmware 1.0.5 which was supposed to cure the uncommanded descent problem.
This looks like you might have a valid warranty claim as the flight data clearly shows the drone failing to maintain altitude and failing to climb with the left stick full forward.

 

[mm crashed]

There some disturbing altitude instability showing up in your flight data from 3:21.5 when you briefly pulled the left stick full down and the drone started slowly climbing from 31 ft to 48 ft at 3:33 even with the left stick down a couple of times and never being pushed upwards.
From 3:33 the drone started coming down very slowly though the left stick was full down (in tripod mode).
You left the left stick in the centre position from 3:37.2 but the drone continued to descend, but climbed from 3:40.6.
At 3:42.2 (40 ft) you pulled the left stick down and the drone descended as it should have and stopped descending when you centred the stick soon after.

But at 3:46 the real trouble showed.
With the left stick centred and the drone hovering, it started losing height.
Within 2.8 secs it hd lost 30 ft.
You went to sport mode and full left stick up to fight the drop.
But it continued to fall.

I see you were using Firmware 1.0.5 which was supposed to cure the uncommanded descent problem.
This looks like you might have a valid warranty claim as the flight data clearly shows the drone failing to maintain altitude and failing to climb with the left stick full forward.

Wow Thanks for the great and detailed feedback. I was pretty confident I didn't crash that drone, but reading your analysis is definitely helpful and I hope DJI comes through

 

[slup]

... I see you were using Firmware 1.0.5 which was supposed to cure the uncommanded descent problem.

This incident doesn't show the usual characteristics from an "uncommanded descent incident" due to deformed rear props.

The motor data don't show motors near max revvs, they aren't commanded to near 100% from the FC & the pitch angle shown in the logs corresponds reasonably well with the piloting & the spec.

The messages in the TXT log isn't the usual "NotEnoughForce" either ... instead like below



Looking at the GPS & IMU velocity differences we see that even though the horizontal plane in east (green) & north (red) behave reasonably ... the vertical (blue) doesn't & goes haywire in the end.



Checking off the DAT event log show messages about height consistency, height control & craft control failure ... all this points instead on a IMU or a baro sensor failure.



But never the less, agree with Meta4 about that this isn't caused by a pilot error, DJI should honor the warranty here & fix this for you.

 

[mm crashed]

This incident doesn't show the usual characteristics from an "uncommanded descent incident" due to deformed rear props.

The motor data don't show motors near max revvs, they aren't commanded to near 100% from the FC & the pitch angle shown in the logs corresponds reasonably well with the piloting & the spec.

The messages in the TXT log isn't the usual "NotEnoughForce" either ... instead like below

View attachment 110403

Looking at the GPS & IMU velocity differences we see that even though the horizontal plane in east (green) & north (red) behave reasonably ... the vertical (blue) doesn't & goes haywire in the end.

View attachment 110404

Checking off the DAT event log show messages about height consistency, height control & craft control failure ... all this points instead on a IMU or a baro sensor failure.

View attachment 110405

But never the less, agree with Meta4 about that this isn't caused by a pilot error, DJI should honor the warranty here & fix this for you.

Thank you very much!!! I contacted DJI today and they said they will review the flight log (I didn't send them the *.dat file) and get back to me. If you think I should send the *.DAT file, i will reach back out to them

 

[slup]

Thank you very much!!! I contacted DJI today and they said they will review the flight log (I didn't send them the *.dat file) and get back to me. If you think I should send the *.DAT file, i will reach back out to them

If you have saved the DAT log aside to your computer it should be sufficient to just sync your flight through the FLY app to the DJI servers .... then they should have it all.